Writing and Interpreting Numerical Expressions Unit 1 Lesson

Writing and Interpreting Numerical Expressions Unit 1 Lesson 1 Math 5

Writing and Interpreting Numerical Expressions • • • Students will be able to: Recognize numerical expressions. Familiarize the words used to represent operations such as addition, subtraction, multiplication and division. Write a numerical expression that record calculations with numbers given a verbal phrase. Translate numerical expressions into words. Interpret numerical expressions without evaluating them. Compare expressions using visual models.

Writing and Interpreting Numerical Expressions Key Vocabulary: Numerical expression Parentheses Operations Addition Subtraction Multiplication Division Tape diagram

Writing and Interpreting Numerical Expressions What are NUMERICAL EXPRESSIONS? A numerical expression is a mathematical phrase that represents a single value. It consists of one or more numbers and operations. These operations involve Addition, Subtraction, Multiplication and Division.

Writing and Interpreting Numerical Expressions What are NUMERICAL EXPRESSIONS? The picture shows the numbers and operations that you can mix up to form a numerical expression. Also, remember that there should be NO equal sign “=” in the expression, because that would be a different story !

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions Writing Numerical Expressions How do I write numerical expressions? In writing numerical expressions from verbal statements, you need to familiarize yourself with the CLUES!!! These clues are words that are used to represent the four operations: addition, subtraction, multiplication and division. These words/phrases are identified on the next slide.

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions Example 1: Write a numerical expression given the verbal phrase below: The sum of nine and five multiplied by three Looking at the given example, you have to understand that you need to get the sum of nine and five first, and multiply whatever the answer is to three. This should be done first the sum of nine and five Then, whatever the answer is multiply it by three

Writing and Interpreting Numerical Expressions So how do we write it as a numerical expression? We need to do some sort of grouping, to indicate that one operation must be done first, before doing another. We use open/close parentheses “( )”, to group the numbers and operations.

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions Example 2: Write a numerical expression given the verbal phrase below: The sum of nine and the product of five and three If you compare it to the first example, both involve the same numbers and the same operations. Example 1: The sum of nine and five multiplied by three Example 2: The sum of nine and the product of five and three

Writing and Interpreting Numerical Expressions Both examples in the previous slide involve numbers nine, five and three, and operations addition and subtraction. But do they really mean the same? BIG NO!!!

Writing and Interpreting Numerical Expressions In Example 2, “The sum of nine and the product of five and three”, the operation that must be done first is to multiply five and three… then add nine to whatever the product is. The grouping will then be:

Writing and Interpreting Numerical Expressions Let’s compare the two verbal phrases!

Writing and Interpreting Numerical Expressions Here, we can say that both verbal statements may have exactly the same numbers and may involve that same operations; they mean differently though. Pay close attention to the given phrase and group the numbers with operations that must be done first. The examples in the previous slide will also give DIFFERENT answers when evaluated.

Writing and Interpreting Numerical Expressions Sample Problem 2: Tell whether the given phrases below have the same meaning, or not, by writing their corresponding numerical expression. a. The difference between twenty and twelve divided by two b. The difference between twenty and the quotient of twelve and two

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions Now, let’s do it the other way around!!! Translating Verbal Phrases into Numerical Expressions Instead of writing numeral expressions given the verbal phrases, you’ll do it the other way around. You are going to translate numerical expressions into words. Remember that the ORDER OF OPERATIONS is very IMPORTANT!!! Always pay attention to: “What should be done first? ”

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions Take note that there are numbers to be grouped in the given example, and should be done first.

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions Sample Problem 3: Translate each numerical expression into words and write them in each cloud.

Writing and Interpreting Numerical Expressions Sample Problem 3: Translate each numerical expression into words and write them in each cloud.

Writing and Interpreting Numerical Expressions Sample Problem 3: Translate each numerical expression into words and write them in each cloud. Solution: (Answers may vary) 1. Four times five plus ten. 2. Four times the sum of five and ten 3. Thirty divided by the sum of five and one times the difference of seven and three 4. Thirty divided by five plus the product of one and seven, minus three

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions Sample Problem 4: Solution:

Writing and Interpreting Numerical Expressions

Writing and Interpreting Numerical Expressions Sample Problem 5 - Solution:

Writing and Interpreting Numerical Expressions Sample Problem 5 - Solution:

Writing and Interpreting Numerical Expressions Sample Problem 6: A pastry box contains 12 pcs of assorted cookies. Paul bought 3 boxes to be given to his parents and 5 boxes for his friends. Draw a tape diagram and write the numerical expression that shows the total number of cookies bought.

Writing and Interpreting Numerical Expressions Sample Problem 6:

Writing and Interpreting Numerical Expressions Sample Problem 6: Solution: